5. 4 Concentrators, PV for Space Applications, and TPV
Concentrators, Concentrator Cells, Solar Cell Efficiencies, Solar Radiation, Calibration
Summary / Abstract:
In this paper we assess the calculation of efficiency for concentrator PV (CPV) devices critically. Based on the general definition and conventional assumptions we argue that the efficiency for CPV devices should not be referenced only to the direct incident irradiance but to the total irradiance which includes also the diffuse and albedo components. The total (spectral) irradiance which would be incident onto a CPV device when the direct irradiance is exactly as already defined in the direct reference spectrum AM1.5D is calculated here and denominated as AM1.5GN. Based on this we derive a correction factor to obtain the thermodynamic efficiencies of CPV from the conventionally quoted efficiency with respect to the direct irradiance only. We illustrate the concept by applying it to the latest published world record efficiencies for CPV.